total rejection of established laws and institutions.
anarchy, terrorism, or other revolutionary activity.
total and absolute destructiveness, especially toward the world at large and including oneself: the power-mad nihilism that marked Hitler's last years.
Philosophy. an extreme form of skepticism: the denial of all real existence or the possibility of an objective basis for truth. nothingness or nonexistence.
(sometimes initial capital letter) the principles of a Russian revolutionary group, active in the latter half of the 19th century, holding that existing social and political institutions must be destroyed in order to clear the way for a new state of society and employing extreme measures, including terrorism and assassination.